The present invention relates to a control device for a hydraulic piston/cylinder unit.
More particularly, it relates to a control device which has a shut-off valve with a valve body cooperating with a valve seat, and a pilot valve member arranged in the valve body and abutting against a valve seat under the action of a spring to control the pressure in a pressure space formed between the valve body and the valve housing.
Such a control device is already known from DE-OS 30 42 277. In this control device it is brought about with the aid of a fine-control shut-off valve--a so-called lowering brake valve--that the load acting on a consumer, for instance, does not proceed in advance of the pressure medium flow associated with the consumer when the load decreases. This shut-off valve has a control valve member which is guided in its valve slide. A control pin of this control valve member projects into an outlet bore hole. Such a shut-off valve has the disadvantage that pressure medium can only flow off when the control pin emerges from the outlet bore hole. The actuating path along which an adjusting device must move the shut-off valve before pressure medium can flow at all is very long.